Did you know arm span ( also known as wingspan or reach ) is approximately equal to height?
How to calculate arm span
We tested this out against a wall using chalk to mark reach and then standing next to the wall to see if it matched height. You should measure from fingertip to fingertip and not have a flat hand as in this photo.
We found my 6 year old’s arm span did equal his height and my 4 year old was a little taller than hers.
What is ape index?
Ape index is the ratio of arm span relative to their height. So my little boy had an ape index of 1.
A arm span greater than height is thought to be advantageous in some sports such as swimming, as longer arms may give greater propulsion. A shorter arm span is useful for weight lifters as they don’t have to lift the weight as high.
How to calculate ape index
Ape Index – Method 1
Wingspan / Height
If ape index is greater than 1, wingspan is greater than height. If ape index is less than one height is greater than wingspan.
Ape Index – Method 2
Wingspan – Height
Ape index calculated this way is either a positive or negative number.
Can you work out your ape index or arm span?
Grab the instructions below. I have a basic investigation instruction sheet and also a slightly different format using a question.
More human body science ideas
Can you work out how many feet tall you are too?
Or , for little ones try some of these great preschool science ideas.
Last Updated on January 21, 2022 by Emma Vanstone